This study, conducted by Francesco P. Cappuccio and colleagues, aimed to systematically review and meta-analyze prospective population-based studies to assess the relationship between sleep duration and the incidence of coronary heart disease (CHD), stroke, and total cardiovascular disease (CVD). The study included 15 studies with a total of 474,684 participants from eight countries, followed for an average of 10 years. The results showed that both short (≤5-6 hours) and long (>8-9 hours) sleep durations were associated with an increased risk of CHD and stroke. Short sleepers had a higher risk of CHD and stroke compared to those sleeping 7-8 hours per night, while long sleepers also exhibited an increased risk. However, the association with total CVD was less consistent, with no significant effect in short sleepers but a statistically significant increased risk in long sleepers. The study concluded that sleeping 9 hours or more per night may be a useful diagnostic tool for detecting subclinical or undiagnosed co-morbidities, while consistently sleeping 5 hours or less per night should be considered a higher-risk group for cardiovascular morbidity and mortality.This study, conducted by Francesco P. Cappuccio and colleagues, aimed to systematically review and meta-analyze prospective population-based studies to assess the relationship between sleep duration and the incidence of coronary heart disease (CHD), stroke, and total cardiovascular disease (CVD). The study included 15 studies with a total of 474,684 participants from eight countries, followed for an average of 10 years. The results showed that both short (≤5-6 hours) and long (>8-9 hours) sleep durations were associated with an increased risk of CHD and stroke. Short sleepers had a higher risk of CHD and stroke compared to those sleeping 7-8 hours per night, while long sleepers also exhibited an increased risk. However, the association with total CVD was less consistent, with no significant effect in short sleepers but a statistically significant increased risk in long sleepers. The study concluded that sleeping 9 hours or more per night may be a useful diagnostic tool for detecting subclinical or undiagnosed co-morbidities, while consistently sleeping 5 hours or less per night should be considered a higher-risk group for cardiovascular morbidity and mortality.